Gharpure SJ, Fartade DJ, Nanda SK, Somani S. Hydroalkoxylation-Initiated Cascade on Sulfone-Tethered Aryl Alkynols Gives Cyclic and Spiro-Heterocyclic β-Ketosulfones.
Org Lett 2023;
25:6155-6160. [PMID:
37561988 DOI:
10.1021/acs.orglett.3c02241]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Serendipitous formation of cyclic β-ketosulfones is observed when sulfone-tethered arylalkynols are reacted with base. The reaction involves a base-promoted propargyl sulfone to the allene isomerization/intramolecular hydroalkoxylation/retro-oxa-Michael/6-endo-trig Michael addition cascade. Sulfone-tethered alkynyl acrylates gave stereoselective access to a diverse array of spirocyclic β-ketosulfone benzofuran/isochroman/indolines and sulfone-tethered bridged bicyclo[3.3.1]nonane. These cyclic β-ketosulfones could be readily elaborated into benzofuran-fused cyclic sulfones and tetracyclic spiroindoline.
Collapse